What Size Amp Do I Need for 2 10 Inch Subs?

what size amp do i need for 2 10 inch subs

One of the most common questions we hear from audio enthusiasts is, “What size amp do I need for 2 10-inch subs?” Well, it’s time to put this query to rest.

Determining the ideal amplifier for your duo subwoofers depends on their total RMS (Root Mean Square) wattage and impedance ratings. To be more specific, you’re looking for an amp that matches your subwoofers’ capabilities and specifications.

For example, if the total RMS of your subs is 600 watts, then you’d need to get an amplifier with an RMS that is around 600 watts as well. In addition, the amp should have a similar ohms rating to the combined impedance of both subs, which varies depending on how you wire the configuration.

Without delay, let’s get into the specifics!

How to Choose the Right Amp Size for 2 10-Inch Subs

Just like a typical speaker, you should also match an amplifier to a subwoofer. This ensures that your devices work efficiently and harmoniously to produce quality sound.

Choosing the right size amplifier for a pair of 10-inch subs leans on the following factors.

1. Power requirements


Identifying the right subwoofer amplifier size starts with understanding their RMS rating. You can think of RMS as the power a subwoofer comfortably handles over time without breaking.

If you have dual subwoofers, you’ll want to add their RMS ratings to get their combined power ratings. Once you have the answer, find an amplifier that matches this power to ensure your subs operate at their best while keeping your sound top-notch.

To illustrate, look at this formula:

RMS rating of subwoofer 1 + RMS rating of subwoofer 2 = total amp power rating

For example, we paired two 10-inch subs of 400-watt RMS each with an 800-watt RMS amp.

As a rule of thumb, never use an amp with excessive or low power. Slight power differences are acceptable. However, huge gaps may result in damage or distorted sound.

2. Impedance matching

It’s also critical to match subwoofer impedance specifications to a compatible amp. Your chosen amp must be capable of supporting the total impedance of the subs to maintain a streamlined flow of power.

Measured in ohms (Ω), you can acquire the appropriate impedance levels in two ways.

1. Manual computation

First, consider whether the subs are wired in parallel (which reduces total impedance) or series (which increases it). Then, get the combined impedance of both subs. Assuming the answer is 4Ω, then a 4-ohm amp should be fitting.

Examine the diagram below:


2. Amp calculator

Alternatively, you can find an online tool that helps you calculate power and impedance. Simply provide the necessary details, and it automatically identifies the right amp size for your subs.

Impedance is a pivotal aspect when choosing an amp. However, as we said, ohm rating changes based on how the coils are wired together.

3. Desired sound quality

Selecting the best amps for subs is crucial in achieving the perfect balance between power and sound quality in your entire audio system. Amplifiers do more than just supply power; they also influence the sound’s character.

Some amps may add more richness to the bass, while others are powerful in delivering clearer, high-frequency sounds. Knowing what kind of sound output you prefer will dictate the perfect amp for your set of 10-inch subs.


Matching your subwoofer with a relevant amplifier isn’t a prerequisite. Thus, we recommend focusing on these parameters: total RMS power, impedance levels, and your preferred sound quality.

We hope your question on “What size amp do I need for 2 10-inch subs?” has been addressed well. With these tips, we’re confident you can create unparalleled sound to keep you entertained and immersed!

5/5 - (1 vote)